I'm a german musician. I*m playing a Yamaha tyros 4 and a korg kronos 88 hammered keys. Both are connected with midi. Tyros midi in Kronos midi out.

The master keyboard is the tyros 4.
I am using the korg to play the fantastic sounds. The stles are from tyros4.

Problem: When I use the key transpose button on my tyros 4 instrument everything is working on the tyros but not on the kronos. The Kronos should be transposed with it at the same time. Is it possible?

The Tyros voices on the Korg keyboard do transpose, but the Kronos could only transposed manualy. Thats not very comfortable and if you forget it it sounds not good when you have a gig.

You say Tyros, MIDI in, and Kronos, MIDI out. Then you say the Tyros is the master. Normally the master is MIDI out.

If you’re playing the Korg and you transpose the Korg, then the Tyros should follow. Transposing simply reassigns note numbers. This happens with the MIDI notes as well. So the actual master keyboard (MIDI out) does the transposing and the other keyboard just plays the “transposed” MIDI notes.

Transposing the “slave” keyboard will have no affect on the master. It should work the other way around. Transposing the master should affect the slave.

I tried to do what you said and it works.
So I can play sounds from my tyros on the kronos and otherwise sounds from kronos on the tyros keys. I connected MIDI A Out from tyros with Midi In at my kronos and Midi Out to MIDI B in at my tyros. So both ways are possible.

When i transpose a song on my tyros and I'm playing the melody on my kronos I can hear the sounds from tyros on the kronos and the tranpose is working.

When I play on my tyros i can hear the sounds from the kronos and the transpose is working too. When I tranpose the melody from 0 to +2 the kronos sounds is also transposed. So everything is fine. But when I play at the same time on my kronos keys and look in the display you can see that the global transpose is set at 0. The global tranpose from the kronos is not switching. That means that I have the same problem as before.

The main question is: Can I transpose the "global transpose" from the kronos when using tyros?

I found a video on youtube which shows that it seems to be possible. But I have no idea what i can do that it will work.

In the video you can see that the tranpose field shows that it is tranposed from an external keyboard. The numbers are switching.

I've not tried this myself but the video does indeed seem to show the Global Transpose of the Kronos changing by MIDI remote. My thought is the Kronos Global MIDI channel should match the "MIDI Transpose Message" coming from the Tyros. Since there can be 16 different channels going back and forth, the Kronos only watches the main channel or Global Channel for certain commands. Also check the MIDI filters in Global making sure sysex messages are not filtered.